Buggy code:
public class Team extends JavaPlugin { protected Logger log ; protected ConnectionManager cm ; protected TeamHandler th ; public EventHandler eh ; protected StatsHandler sh ; private final TeamCommand teamCommand = new TeamCommand ( this ) ; @ Override public void onDisable ( ) { } @ Override public void onEnable ( ) { } private void initialize ( ) { } private void initializeEvents ( ) { eh . RegisterCallback ( new EventHandler . EventCallback ( ) { public void run ( int parent , int child , String data ) { getServer ( ) . broadcastMessage ( ( ( ( ( ( ( ( ChatColor . GOLD ) + ( th . playerGetName ( parent ) ) ) + "<seq2seq4repair_space>created<seq2seq4repair_space>a<seq2seq4repair_space>new<seq2seq4repair_space>team,<seq2seq4repair_space>" ) + ( ChatColor . WHITE ) ) + ( th . teamGetName ( child ) ) ) + ( ChatColor . GOLD ) ) + "!" ) ) ; } } , TeamCreate ) ; eh . RegisterCallback ( new EventHandler . EventCallback ( ) { public void run ( int parent , int child , String data ) { getServer ( ) . broadcastMessage ( ( ( ( ( ( ( ( ChatColor . GOLD ) + ( th . playerGetName ( parent ) ) ) + "<seq2seq4repair_space>disbanded<seq2seq4repair_space>the<seq2seq4repair_space>team<seq2seq4repair_space>" ) + ( ChatColor . WHITE ) ) + ( th . teamGetName ( child ) ) ) + ( ChatColor . GOLD ) ) + "!" ) ) ; th . teamSendToMembers ( child , ( ( ChatColor . RED ) + "disbanded." ) ) ; } } , TeamDisband ) ; eh . RegisterCallback ( new EventHandler . EventCallback ( ) { public void run ( int parent , int child , String data ) { th . teamSendToMembers ( child , TeamUtils . formatTeam ( sh . GetTeamStats ( child ) , data ) ) ; } } , TeamMotd ) ; eh . RegisterCallback ( new EventHandler . EventCallback ( ) { public void run ( int parent , int child , String data ) { th . teamSendToMembers ( child , ( ( ( ChatColor . GOLD ) + ( th . playerGetName ( parent ) ) ) + "<seq2seq4repair_space>joined!" ) ) ; } } , PlayerJoin ) ; eh . RegisterCallback ( new EventHandler . EventCallback ( ) { public void run ( int parent , int child , String data ) { th . teamSendToMembers ( child , ( ( ( ChatColor . GOLD ) + ( th . playerGetName ( parent ) ) ) + "<seq2seq4repair_space>left!" ) ) ; } } , PlayerLeave ) ; eh . RegisterCallback ( new EventHandler . EventCallback ( ) { public void run ( int parent , int child , String data ) { th . teamSendToMembers ( child , ( ( ( ChatColor . GOLD ) + ( th . playerGetName ( parent ) ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>now<seq2seq4repair_space>invited!" ) ) ; } } , PlayerInvite ) ; eh . RegisterCallback ( new EventHandler . EventCallback ( ) { public void run ( int parent , int child , String data ) { th . teamSendToMembers ( child , ( ( ( ChatColor . GOLD ) + ( th . playerGetName ( parent ) ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>no<seq2seq4repair_space>longer<seq2seq4repair_space>invited!" ) ) ; } } , PlayerDeinvite ) ; eh . RegisterCallback ( new EventHandler . EventCallback ( ) { public void run ( int parent , int child , String data ) { th . teamSendToMembers ( child , ( ( ( ChatColor . GOLD ) + ( th . playerGetName ( parent ) ) ) + "<seq2seq4repair_space>was<seq2seq4repair_space>kicked!" ) ) ; } } , PlayerKicked ) ; eh . RegisterCallback ( new EventHandler . EventCallback ( ) { public void run ( int parent , int child , String data ) { if ( th . teamChatter . contains ( parent ) ) <START_BUG> th . teamChatter . remove ( parent ) ; <END_BUG> } } , PlayerDeath ) ; } }

Fix:
th . teamChatter . remove ( ( ( Integer ) ( parent ) ) ) ;